llvm-6502/include/llvm/System/TimeValue.h
2005-05-05 22:33:09 +00:00

384 lines
14 KiB
C++

//===-- TimeValue.h - Declare OS TimeValue Concept --------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Reid Spencer and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This header file declares the operating system TimeValue concept.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/DataTypes.h"
#include <string>
#ifndef LLVM_SYSTEM_TIMEVALUE_H
#define LLVM_SYSTEM_TIMEVALUE_H
namespace llvm {
namespace sys {
/// This class is used where a precise fixed point in time is required. The
/// range of TimeValue spans many hundreds of billions of years both past and
/// present. The precision of TimeValue is to the nanosecond. However, the
/// actual precision of its values will be determined by the resolution of
/// the system clock. The TimeValue class is used in conjunction with several
/// other lib/System interfaces to specify the time at which a call should
/// timeout, etc.
/// @since 1.4
/// @brief Provides an abstraction for a fixed point in time.
class TimeValue {
/// @name Constants
/// @{
public:
/// A constant TimeValue representing the smallest time
/// value permissable by the class. MinTime is some point
/// in the distant past, about 300 billion years BCE.
/// @brief The smallest possible time value.
static const TimeValue MinTime;
/// A constant TimeValue representing the largest time
/// value permissable by the class. MaxTime is some point
/// in the distant future, about 300 billion years AD.
/// @brief The largest possible time value.
static const TimeValue MaxTime;
/// A constant TimeValue representing the base time,
/// or zero time of 00:00:00 (midnight) January 1st, 2000.
/// @brief 00:00:00 Jan 1, 2000 UTC.
static const TimeValue ZeroTime;
/// A constant TimeValue for the Posix base time which is
/// 00:00:00 (midnight) January 1st, 1970.
/// @brief 00:00:00 Jan 1, 1970 UTC.
static const TimeValue PosixZeroTime;
/// A constant TimeValue for the Win32 base time which is
/// 00:00:00 (midnight) January 1st, 1601.
/// @brief 00:00:00 Jan 1, 1601 UTC.
static const TimeValue Win32ZeroTime;
/// @}
/// @name Types
/// @{
public:
typedef int64_t SecondsType; ///< Type used for representing seconds.
typedef int32_t NanoSecondsType; ///< Type used for representing nanoseconds.
enum TimeConversions {
NANOSECONDS_PER_SECOND = 1000000000, ///< One Billion
MICROSECONDS_PER_SECOND = 1000000, ///< One Million
MILLISECONDS_PER_SECOND = 1000, ///< One Thousand
NANOSECONDS_PER_MICROSECOND = 1000, ///< One Thousand
NANOSECONDS_PER_MILLISECOND = 1000000,///< One Million
NANOSECONDS_PER_POSIX_TICK = 100, ///< Posix tick is 100 Hz (10ms)
NANOSECONDS_PER_WIN32_TICK = 100, ///< Win32 tick is 100 Hz (10ms)
};
/// @}
/// @name Constructors
/// @{
public:
/// Caller provides the exact value in seconds and nanoseconds. The
/// \p nanos argument defaults to zero for convenience.
/// @brief Explicit constructor
explicit TimeValue (SecondsType seconds, NanoSecondsType nanos = 0)
: seconds_( seconds ), nanos_( nanos ) { this->normalize(); }
/// Caller provides the exact value as a double in seconds with the
/// fractional part representing nanoseconds.
/// @brief Double Constructor.
explicit TimeValue( double new_time )
: seconds_( 0 ) , nanos_ ( 0 ) {
SecondsType integer_part = static_cast<SecondsType>( new_time );
seconds_ = integer_part;
nanos_ = static_cast<NanoSecondsType>( (new_time -
static_cast<double>(integer_part)) * NANOSECONDS_PER_SECOND );
this->normalize();
}
/// This is a static constructor that returns a TimeValue that represents
/// the current time.
/// @brief Creates a TimeValue with the current time (UTC).
static TimeValue now();
/// @}
/// @name Operators
/// @{
public:
/// Add \p that to \p this.
/// @returns this
/// @brief Incrementing assignment operator.
TimeValue& operator += (const TimeValue& that ) {
this->seconds_ += that.seconds_ ;
this->nanos_ += that.nanos_ ;
this->normalize();
return *this;
}
/// Subtract \p that from \p this.
/// @returns this
/// @brief Decrementing assignment operator.
TimeValue& operator -= (const TimeValue &that ) {
this->seconds_ -= that.seconds_ ;
this->nanos_ -= that.nanos_ ;
this->normalize();
return *this;
}
/// Determine if \p this is less than \p that.
/// @returns True iff *this < that.
/// @brief True if this < that.
int operator < (const TimeValue &that) const { return that > *this; }
/// Determine if \p this is greather than \p that.
/// @returns True iff *this > that.
/// @brief True if this > that.
int operator > (const TimeValue &that) const {
if ( this->seconds_ > that.seconds_ ) {
return 1;
} else if ( this->seconds_ == that.seconds_ ) {
if ( this->nanos_ > that.nanos_ ) return 1;
}
return 0;
}
/// Determine if \p this is less than or equal to \p that.
/// @returns True iff *this <= that.
/// @brief True if this <= that.
int operator <= (const TimeValue &that) const { return that >= *this; }
/// Determine if \p this is greater than or equal to \p that.
/// @returns True iff *this >= that.
/// @brief True if this >= that.
int operator >= (const TimeValue &that) const {
if ( this->seconds_ > that.seconds_ ) {
return 1;
} else if ( this->seconds_ == that.seconds_ ) {
if ( this->nanos_ >= that.nanos_ ) return 1;
}
return 0;
}
/// Determines if two TimeValue objects represent the same moment in time.
/// @brief True iff *this == that.
/// @brief True if this == that.
int operator == (const TimeValue &that) const {
return (this->seconds_ == that.seconds_) &&
(this->nanos_ == that.nanos_);
}
/// Determines if two TimeValue objects represent times that are not the
/// same.
/// @return True iff *this != that.
/// @brief True if this != that.
int operator != (const TimeValue &that) const { return !(*this == that); }
/// Adds two TimeValue objects together.
/// @returns The sum of the two operands as a new TimeValue
/// @brief Addition operator.
friend TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2);
/// Subtracts two TimeValue objects.
/// @returns The difference of the two operands as a new TimeValue
/// @brief Subtraction operator.
friend TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2);
/// @}
/// @name Accessors
/// @{
public:
/// Returns only the seconds component of the TimeValue. The nanoseconds
/// portion is ignored. No rounding is performed.
/// @brief Retrieve the seconds component
SecondsType seconds() const { return seconds_; }
/// Returns only the nanoseconds component of the TimeValue. The seconds
/// portion is ignored.
/// @brief Retrieve the nanoseconds component.
NanoSecondsType nanoseconds() const { return nanos_; }
/// Returns only the fractional portion of the TimeValue rounded down to the
/// nearest microsecond (divide by one thousand).
/// @brief Retrieve the fractional part as microseconds;
uint32_t microseconds() const {
return nanos_ / NANOSECONDS_PER_MICROSECOND;
}
/// Returns only the fractional portion of the TimeValue rounded down to the
/// nearest millisecond (divide by one million).
/// @brief Retrieve the fractional part as milliseconds;
uint32_t milliseconds() const {
return nanos_ / NANOSECONDS_PER_MILLISECOND;
}
/// Returns the TimeValue as a number of microseconds. Note that the value
/// returned can overflow because the range of a uint64_t is smaller than
/// the range of a TimeValue. Nevertheless, this is useful on some operating
/// systems and is therefore provided.
/// @brief Convert to a number of microseconds (can overflow)
uint64_t usec() const {
return seconds_ * MICROSECONDS_PER_SECOND +
( nanos_ / NANOSECONDS_PER_MICROSECOND );
}
/// Returns the TimeValue as a number of milliseconds. Note that the value
/// returned can overflow because the range of a uint64_t is smaller than
/// the range of a TimeValue. Nevertheless, this is useful on some operating
/// systems and is therefore provided.
/// @brief Convert to a number of milliseconds (can overflow)
uint64_t msec() const {
return seconds_ * MILLISECONDS_PER_SECOND +
( nanos_ / NANOSECONDS_PER_MILLISECOND );
}
/// Converts the TimeValue into the corresponding number of "ticks" for
/// Posix, correcting for the difference in Posix zero time.
/// @brief Convert to unix time (100 nanoseconds since 12:00:00a Jan 1,1970)
uint64_t toPosixTime() const {
uint64_t result = seconds_ - PosixZeroTime.seconds_;
result += nanos_ / NANOSECONDS_PER_POSIX_TICK;
return result;
}
/// Converts the TimeValue into the corresponding number of seconds
/// since the epoch (00:00:00 Jan 1,1970).
uint64_t toEpochTime() const {
return seconds_ - PosixZeroTime.seconds_;
}
/// Converts the TiemValue into the correspodning number of "ticks" for
/// Win32 platforms, correcting for the difference in Win32 zero time.
/// @brief Convert to windows time (seconds since 12:00:00a Jan 1, 1601)
uint64_t toWin32Time() const {
uint64_t result = seconds_ - Win32ZeroTime.seconds_;
result += nanos_ / NANOSECONDS_PER_WIN32_TICK;
return result;
}
/// Provides the seconds and nanoseconds as results in its arguments after
/// correction for the Posix zero time.
/// @brief Convert to timespec time (ala POSIX.1b)
void getTimespecTime( uint64_t& seconds, uint32_t& nanos ) const {
seconds = seconds_ - PosixZeroTime.seconds_;
nanos = nanos_;
}
/// Provides conversion of the TimeValue into a readable time & date.
/// @returns std::string containing the readable time value
/// @brief Convert time to a string.
std::string toString() const;
/// @}
/// @name Mutators
/// @{
public:
/// The seconds component of the TimeValue is set to \p sec without
/// modifying the nanoseconds part. This is useful for whole second
/// arithmetic.
/// @brief Set the seconds component.
void seconds (SecondsType sec ) {
this->seconds_ = sec;
this->normalize();
}
/// The nanoseconds component of the TimeValue is set to \p nanos without
/// modifying the seconds part. This is useful for basic computations
/// involving just the nanoseconds portion. Note that the TimeValue will be
/// normalized after this call so that the fractional (nanoseconds) portion
/// will have the smallest equivalent value.
/// @brief Set the nanoseconds component using a number of nanoseconds.
void nanoseconds ( NanoSecondsType nanos ) {
this->nanos_ = nanos;
this->normalize();
}
/// The seconds component remains unchanged.
/// @brief Set the nanoseconds component using a number of microseconds.
void microseconds ( int32_t micros ) {
this->nanos_ = micros * NANOSECONDS_PER_MICROSECOND;
this->normalize();
};
/// The seconds component remains unchanged.
/// @brief Set the nanoseconds component using a number of milliseconds.
void milliseconds ( int32_t millis ) {
this->nanos_ = millis * NANOSECONDS_PER_MILLISECOND;
this->normalize();
};
/// @brief Converts from microsecond format to TimeValue format
void usec( int64_t microseconds ) {
this->seconds_ = microseconds / MICROSECONDS_PER_SECOND;
this->nanos_ = NanoSecondsType(microseconds % MICROSECONDS_PER_SECOND) *
NANOSECONDS_PER_MICROSECOND;
this->normalize();
}
/// @brief Converts from millisecond format to TimeValue format
void msec( int64_t milliseconds ) {
this->seconds_ = milliseconds / MILLISECONDS_PER_SECOND;
this->nanos_ = NanoSecondsType(milliseconds % MILLISECONDS_PER_SECOND) *
NANOSECONDS_PER_MILLISECOND;
this->normalize();
}
/// Converts the \p seconds argument from PosixTime to the corresponding
/// TimeValue and assigns that value to \p this.
/// @brief Convert seconds form PosixTime to TimeValue
void fromEpochTime( SecondsType seconds ) {
seconds_ = seconds + PosixZeroTime.seconds_;
nanos_ = 0;
this->normalize();
}
/// Converts the \p win32Time argument from Windows FILETIME to the
/// corresponding TimeValue and assigns that value to \p this.
/// @brief Convert seconds form Windows FILETIME to TimeValue
void fromWin32Time( uint64_t win32Time ) {
this->seconds_ = win32Time / 10000000 + Win32ZeroTime.seconds_;
this->nanos_ = NanoSecondsType(win32Time % 10000000) * 100;
}
/// @}
/// @name Implementation
/// @{
private:
/// This causes the values to be represented so that the fractional
/// part is minimized, possibly incrementing the seconds part.
/// @brief Normalize to canonical form.
void normalize();
/// @}
/// @name Data
/// @{
private:
/// Store the values as a <timeval>.
SecondsType seconds_;///< Stores the seconds part of the TimeVal
NanoSecondsType nanos_; ///< Stores the nanoseconds part of the TimeVal
/// @}
};
inline TimeValue operator + (const TimeValue &tv1, const TimeValue &tv2) {
TimeValue sum (tv1.seconds_ + tv2.seconds_, tv1.nanos_ + tv2.nanos_);
sum.normalize ();
return sum;
}
inline TimeValue operator - (const TimeValue &tv1, const TimeValue &tv2) {
TimeValue difference (tv1.seconds_ - tv2.seconds_, tv1.nanos_ - tv2.nanos_ );
difference.normalize ();
return difference;
}
}
}
#endif